In a conventional camera, the objective lens diaphragm aperture and the shutter speed for flash photography were controlled in such a manner that the diaphragm aperture is controlled depending upon the camera-to-object distance, for instance, to F 5.6 when the object is near from the camera and F 2.8 when the object is at a distance from the camera respectively, and that the shutter speed is controlled to approximately 1/60 second which is the highest flash synchronizable speed. In other known flash photography exposure control system, a range finding device incorporated in the camera measures the camera-to-object distance prior to the exposure and the diaphragm aperture is controlled in accordance with the mesured distance, with the shutter speed being adjusted to the highest flash synchronizable speed.
However, in such exposure control systems, the ambient light and the brightness condition of the portions other than the principal target object in the objective scenery were not taken into account. When a picture is taken for a scene where a person to be photographed stands in a dark scenery, although a proper amount of exposure is given to the person as the principal object which is illuminated by the flash light, the diaphragm aperture and the shutter speed at that time can not give sufficient exposure for the surroundings of the principal object because they are ordinarily further away from the camera than the principal object and receives little amount of flash light. As the result, the surrounding are reproduced dark in the resultant picture with the principal object having been photographed with a proper exposure.